It seems my blog post here is going to be a bit different than the others. Not so much academia, more nerdiness, but lots of floofs.
So, I get that most people hate to be told that they are wrong about something, but this whole blog post is about how you’re (probably) wrong about how evolution works. But, it’s totally not your fault! So much science communication about evolution gets it wrong too! What I’m talking about is the tendency for people to talk about evolution as if it has a purpose. The thing is, it doesn’t really…
If we go back to the basics, evolution has two main parts. Random mutations (or as Darwin called it, variation), and selection (e.g. when one mutation or variant is better than another). How these two parts play together is really what evolution is about, but often, the selection part is talked about as if it has a purpose or an end goal in mind. It doesn’t. Really, what selection means is that one type of an organism can make more offspring than another. Let’s look at this with pretend animals called floofs.
Let’s say there’s a big group of floofs, some of them very different to others, bigger, smaller, blue floofs, purple floofs, round ones, square ones, fluffier floofs, and less fluffy ones – you get the picture. All these different floofs came about because of mutations. These floofs all live together on a nice warm beach by the Pacific Ocean. Think about this beach, and what it’s like – nice and hot, lots of sand, waves crashing in, palm trees… sorry… got carried away day dreaming there! So, back to the floofs. On that tropical beach. You can imagine that being one of the fluffier floofs isn’t actually great on a tropical beach, and, indeed, it’s not. These poor floofs get heat stroke and can’t swim well in the ocean, so (sadly) they die much sooner than the less fluffy floofs. This also means that they tend to not have as many baby floofs, so their genes aren’t in that population so much. But, this doesn’t mean that evolution wants to make the floofs less fluffy; in fact there’s another population of floofs that lives on a giant mountain right next to the beach AND OH MY GOODNESS THEY’RE SO FLUFFY.
So, you see, evolution and selection don’t have goals, it’s just that whatever happens to work for an organism in a given environment tends to stick around.
I mean, you don’t even have to look very far for examples of things evolution has gotten a bit silly. Just look at your arms next time you get a bit chilly, those goose bumps (caused by arrector pili muscles pulling on the hair) aren’t actually useful since we don’t have fur! Another great, but probably more painful example, is wisdom teeth. It’s thought that our ancestors ate much more fibrous foods (aka plants) and that the wisdom teeth helped grind up this food. But now, our jaws are smaller, and we tend to not need to grind our food down with our teeth so much these days, so wisdom teeth can kind of get in the way.
There’s also lots of animals that you might look at and say “oh dear, Evolution, what in the world were you thinking?!” (Just a reminder, Evolution wasn’t thinking – it can’t.) One of my personal favourites is the velvet worm. They’re kind of related to insects, but they are so much weirder. Velvet worms have lots of legs, but they’re squishy (like the rest of their body), and to catch their food, they squirt slime at it. All round just strange animals, I’m pretty sure even I don’t know all the strange facts about velvet worms… feel free to look up a bit more about them!
There are so many odd creatures, extinct and still alive, that you have to wonder at the diversity of nature. All of this from a process with no real end goal… let me know if you have a favourite strange animal! I always like learning more about the oddities of evolution.